The annexation of Texas in 1845 was a significant factor leading to the Civil War for several reasons. First, Texas was a slave state, and its admission to the Union intensified the national debate over slavery.
When Texas joined the Union, it added over 300,000 square miles of territory where slavery was permitted. This raised the stakes in the ongoing conflict between free and slave states. The balance between these two groups in Congress was crucial; any new state that entered the Union could tip that balance and influence future legislation regarding slavery.
Additionally, the annexation was tied to the concept of Manifest Destiny, the belief that the United States was destined to expand across the continent. This idea fueled further desires for expansion but often came at the cost of exacerbating tensions between North and South about the expansion of slavery into new territories.
Moreover, the annexation of Texas led directly to the Mexican-American War (1846-1848). The war resulted in significant territorial gains for the United States but also brought forth the contentious issue of whether the new territories acquired would be free or slave. The ensuing debates and legislative battles, such as the Compromise of 1850, failed to settle the sectional disputes and instead highlighted the divisions between North and South.
In summary, the annexation of Texas not only expanded the nation’s boundaries but also significantly escalated the tensions and divisions over slavery, ultimately contributing to the outbreak of the Civil War.